Military, commercial and private aircraft are equipped with a variety of cockpit instrumentation including flight computers, Primary Flight Displays (PFD), radios and gauges. A particular cockpit instrument is known as a Flight Management System (FMS) which formats FMS navigation data and forwards the data to a display system for display during flight for a pilot. The FMS navigation data can include waypoints, distances and headings between waypoints, airports and navaids, and are displayed in real-time during flight to chart a course from an origination point to a destination point. Prior to flight, the latitude and longitude of the various waypoints, airports, and navaids are programmed into the FMS computer to chart the intended course, forming a portion of the flight plan.
Referring to FIG. 1, there is illustrated a conventional FMS display illustrating various waypoints 12 plotted along a course from an origination point A to a destination point B. Each waypoint 12 is symbolically represented by a triangle symbol, and has associated therewith a latitude and a longitude abbreviated as LAT and LNG, respectively. A line interconnects the various waypoint triangular symbols 12, and may be further identified with a distance in nautical miles, as well as a heading in degrees between the associated waypoints. The autopilot may fly the aircraft point to point based on the latitude and longitude points of the waypoints, or the pilot may manually fly the aircraft the identified distance at the identified heading along the charted course.
Other flight computers are provided with other various information including Instrument Flight Rule (IFR) charts, and Visual Flight Rule (VFR) charts which identify various other navigation data including weather maps, approach charts, airports, cities and navaids. Each chart corresponds to a representative small portion of the earth. During flight, the pilot may ascertain the IFR and VFR charts individually to determine weather conditions and the airports proximate the aircraft during flight as well as various cities, geographic landmarks and terrain to aid in navigation. These IFR and VFR charts may further be provided with filters, such as filters to screen out the airports that have suitable landing facilities for the particular aircraft should there be an emergency. For instance, if the aircraft is a Fokker 100, the VFR charts may have a filter visually rendering and identifying only airports having suitable landing facilities for this particular aircraft.
One problem with conventional aircraft systems is that these IFR and VFR charts are only alternately displayed upon selection, and are not simultaneously displayed with the FMS navigation data including waypoints. The IFR and VFR charts are typically comprised of bitmapped image data that is stored in memory, and typically form rectangular charts, each corner of the chart having a specific latitude and longitude.
One particular problem is that these rectangular bitmapped charts are rectangular, yet the earth is a sphere and thus has a curved surface. Hence, while the charts are stored in memory as rectangular charts, the charts cannot simply be tiled together to represent a portion of the earth and simultaneously displayed with FMS navigation data since the chart corners, chart data and FMS navigation data do not necessarily align and register with one another due to the curvature of the earth.
FIG. 2 illustrates this problem. If the rectangular bitmapped data charts 14 were simply tiled together and merged with the FMS navigation data, the various airport and navaid symbols will not align and register with the various waypoint symbols, especially when the waypoint and the airport or navaid, for instance, have an identical latitude and longitude. For instance, the airport symbol 16 representing Longview, Tex., labeled as LNG, does not align with the associated waypoint 12 even though they have a common latitude and longitude. Again, this is due to the fact that the earth has a curved surface and causes the FMS data to be skewed from the bitmapped data of the VFR chart. Likewise, other VFR and IFR data including approach charts, weather radar and so forth will tend to be skewed from the FMS data if the bitmapped charts were simply merged with the FMS data as shown in FIG. 2.
There is desired an improved aircraft display including an improved Flight Management System (FMS) that can integrate the bitmapped data charts such that the bitmapped data is properly registered and simultaneously displayed with the FMS navigation data including waypoints.